Reviews and syntheses

Author(s)
Alexander Braun, Marina Spona-Friedl, Maria Avramov, Martin Elsner, Federico Baltar, Thomas Reinthaler, Gerhard J. Herndl, Christian Griebler
Abstract

Heterotrophic CO2 fixation is a significant yet underappreciated CO2 flux in environmental carbon cycling. In contrast to photosynthesis and chemolithoautotrophy - the main recognized autotrophic CO2 fixation pathways - the importance of heterotrophic CO2 fixation remains enigmatic. All heterotrophs - from microorganisms to humans - take up CO2 and incorporate it into their biomass. Depending on the availability and quality of growth substrates, and drivers such as the CO2 partial pressure, heterotrophic CO2 fixation contributes at least 1%-5% and in the case of methanotrophs up to 50% of the carbon biomass. Assuming a standing stock of global heterotrophic biomass of 47-85PgC, we roughly estimate that up to 5PgC might be derived from heterotrophic CO2 fixation, and up to 12PgCyr-1 originating from heterotrophic CO2 fixation is funneled into the global annual heterotrophic production of 34-245PgCyr-1. These first estimates on the importance of heterotrophic fixation of inorganic carbon indicate that this pathway should be incorporated in present and future carbon cycling budgets.

Organisation(s)
Functional and Evolutionary Ecology
External organisation(s)
Helmholtz-Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Journal
Biogeosciences
Volume
18
Pages
3689-3700
No. of pages
12
ISSN
1726-4170
DOI
https://doi.org/10.5194/bg-18-3689-2021
Publication date
06-2021
Peer reviewed
Yes
Austrian Fields of Science 2012
106026 Ecosystem research
ASJC Scopus subject areas
Ecology, Evolution, Behavior and Systematics, Earth-Surface Processes
Portal url
https://ucris.univie.ac.at/portal/en/publications/reviews-and-syntheses(cc33c2aa-fb1b-42fd-bd31-79020f1f808e).html